1. Field of the Invention
The present invention relates to a data writing and reproducing apparatus and method for transferring and storing audio data, which is written in a removable recording medium such as a music CD (Compact Disc), in a built-in storage medium at a higher data rate than the rate prescribed for playback of the music CD.
2. Description of the Related Art
A so-called CD changer containing many CDs and automatically reproducing audio data recorded on the CDs is well known. In such a CD changer, several tens to several hundreds of CDs are contained in one housing, and one of the CDs is selected with a predetermined operation for automatic playback. Audio data recorded on the CDs can be reproduced orderly for each of the CDs or at random, in units of one CD or one piece of music recorded on each CD, by selecting a plurality of CDs. That type of CD changer is mostly employed in stationary fashion, that is, by being installed in a room.
The above-described CD changer, however, had a difficulty in realizing continuous playback because a CD exchange time was required even in the automatic playback mode. Also, a CD changer containing 100, 200 or more CDs was very inconvenient to carry and install in place because of the increased size and weight of the housing.
To overcome those problems, instead of the CD changer, there has been proposed an audio server employing a storage medium, such as a hard disk drive, which is relatively small in size, but has a large storage capacity. In the audio server, audio data recorded on each CD is read, and the read-out audio data is coded and compressed by a predetermined method. The compressed data is written and stored in the hard disk drive. By using a hard disk drive having a storage capacity on the order of 6 GByte, data of about 1000 pieces of music can be written. The audio server is superior to the above-described CD changer in that continuous playback can be easily realized because of not requiring exchanging CDs unlike the CD changer, and in that the housing size can be reduced even though a larger amount of music data can be written in one unit of the hard disk drive.
Further, in the audio server, when audio data recorded on a CD is written and stored in a hard disk drive, the audio data can be handled in the same manner as ordinary digital data. Accordingly, data can be written and stored in a shorter time than the playback time prescribed for a musical composition or the like, which has been recorded on a CD, by rotating the CD at a higher speed than the standard rotational speed prescribed for the CD and thereby reading the data out of the CD at a higher rate.
In the conventional audio server described above, however, during the time in which audio data recorded on a CD is written and stored in a hard disk drive, the audio server is exclusively employed for the process of writing and storing the data. This has given rise to a problem that the user has nothing to do other than just waiting until the writing process has ended.
For example, even when a 20×CD-ROM drive capable of rotating at an average rotational speed about 20 times as fast as the prescribed speed is employed for playback of a CD, about three minutes is required for a CD having a record time of 60 minutes until the writing process has ended. Such a waiting time makes the user feel irritated and impatient. To avoid the above drawback, it has been proposed to provide a user interface such as a certain display on an audio server. Even with the proposal, however, the user is obliged to wait until the end of the writing process while viewing a message, for example, “Under Copying”, indicated on a screen of the display to inform the user of such a state that the process of writing and storing the data is being executed, while hearing a beep or other like tones.
On the other hand, there has also been proposed a portable audio data player using a hard disk drive or a semiconductor memory as a storage or recording medium. The portable audio data player is connected to the above-described audio server, and audio data stored in the audio server is transferred to the portable audio data player and stored in the storage or recording medium. Assuming that the storage or recording medium has a capacity on the order of 200 MB, for example, audio data can be stored with a playback time of several tens of minutes.
When audio data is transferred from the audio server to the portable audio data player in such a way, a similar problem as described above has also been experienced, that is to say, the user has to just wait until the end of the data transfer.